The present invention relates to an arrangement for closing and opening a film sheet cassette, and a film sheet cassette provided with such an arrangement. More particularly, the invention is concerned with an X-ray cassette and an arrangement for opening and closing of the same.
Known film sheet cassettes have a bottom part and a top part movable between open and closed positions, wherein an arrangement for opening and closing the same has a sliding element which is retained in the closed position by a spring and has a hook engageable in a projection of the top element in the closed position. In the known cassettes, the top element or cassette cover is connected with an edge of the bottom element by a hinge, and the closing or locking elements are located either at the side which is opposite to the hinge, or at both sides extending from the side where the hinge is provided. Cassettes are also known in which the cover element is placed onto the bottom element in a substantially parallel direction and fixed by the closing elements at at least two opposite sides.
In the cassettes of the abovementioned type, the closing of the cassette is performed by the user by pressing the cover element onto the bottom element and displacing of the sliding element in a direction transverse to the closing direction of the cover element. In this construction, an element which is generally arranged on the cover element presses onto an inclined surface of the sliding element which is guided on the bottom element, so that the sliding element is displaced from its closed position. Thereby, in order to provide for this action the user must often apply relatively high force. It has also been shown that when several closing or locking elements are provided, one of the locking elements is often not completely actuated so that the cassette after some manipulations remains open at one corner.